📚 The Most Common Word

This project provides a Python function that identifies the most frequently occurring word in a given text and returns its count. It includes tests to validate its functionality, ensuring reliability and robustness.

🛠️ Features

• Extracts and counts words using regular expressions and Python's Counter class.
• Handles case insensitivity, special characters, and edge cases like empty text or ties.
• Fully tested with pytest and type-checked using mypy.

🔧 Installation

This project uses Poetry for dependency management. To set up the environment, follow these steps:

1. Clone the repository:

   git clone [email protected]:Kinetics20/the_most_common_word.git
   cd the_most_common_word

Install Dependencies

To install Poetry, Mypy and Pytest on Linux or macOS, use the following command:

pipx install poetry
poetry add mypy
poetry add 'pytest==8.3.4'

🚀 Usage

The main function most_common_word analyzes a given text and returns the most frequent word.
Example Code:

from common_word import most_common_word

text = "Home is where I feel safe, but the house I grew up in will always be home to me."
result = most_common_word(text)
print(result)  # Output: ('home', 2)

✅ Tests

The project includes unit tests written using pytest to validate the function’s behavior.
Run Tests:

pytest test_common_word.py -vv

Test Results:

================================================================ test session starts =================================================================
platform linux -- Python 3.12.3, pytest-8.3.4
collected 6 items

test_common_word.py::test_most_common_word_basic PASSED                                                                                        
test_common_word.py::test_most_common_word_case_insensitivity PASSED                                                                           
test_common_word.py::test_most_common_word_empty_text PASSED                                                                                   
test_common_word.py::test_most_common_word_special_characters PASSED                                                                           
test_common_word.py::test_most_common_word_tie PASSED                                                                                          
test_common_word.py::test_most_common_word_single_word PASSED                                                                                  

================================================================= 6 passed in 0.02s ================================================================

🧪 Type Checking

Static typing was enforced with mypy for code clarity and safety.
Run mypy:

mypy common_word.py

📄 Function Description

import re
from collections import Counter

def most_common_word(txt: str) -> tuple[str, int]:
    """
    Function returns the most frequently occurring word in the text and its count.

    Args:
         txt (str): The text to analyse.

    Returns:
        tuple[str, int]: The most frequently occurring word in the text.
    """
    words: list[str] = re.findall(r'\b\w+\b', txt.lower())
    if not words:
        return '', 0

    word_counts: Counter[str] = Counter(words)
    return word_counts.most_common(n=1)[0]

📝 Test Cases

Test Case	Input	Expected Output
Basic Word Count	"Home is where I feel safe, but the house I grew up in will always be home to me."	('home', 2)
Case Insensitivity	"In a small city... the City of Angels... city’s vibrant energy."	('city', 3)
Empty Text	""	('', 0)
Special Characters	"@ The sun rises... $sun is$ high in the sky... feel the warmth^ of the sun..."	('the', 6)
Tie Between Words	"Birds fly high, and fish swim deep while birds and fish explore nature."	('birds', 2)
Single Word	"Home"	('home', 1)

💻 Technologies Used

• Python (3.12.3)
• Poetry for dependency management
• pytest for unit testing
• mypy for static type checking
• re module for regular expressions
• collections.Counter for word counting

🎉 Results

All tests passed successfully, confirming that the function works as expected across various scenarios.

🧑‍💻 Author

Piotr Lipiński

Feel free to contribute, submit issues, or ask questions! 😊